Denver Broncos running back Lance Ball, right, takes a handoff from quarterback Ryan Katz during drills at off season training camp at the NFL football team's training facility in Englewood, Colo., on Monday, June 3, 2013. (AP Photo/Ed Andrieski)

The grizzled running back skipped some of last year's offseason workouts, then showed up at the mandatory minicamp and handily won the Denver Broncos' starting job during training camp.

His absence this time around is much more of a gamble.

McGahee is pushing 32, he's coming off a serious knee injury, he's set to make $2.5 million this season and the void he left at practice has been filled nicely by second-year speedster Ronnie Hillman and rookie Montee Ball, who scored an NCAA-record 83 touchdowns at Wisconsin.

Then there's Jacob Hester, whose versatility makes him an ideal fit for a team that's revving up the high-octane offense, former first-round pick Knowshon Moreno, who practiced in team drills Monday for the first time since injuring his right knee in the playoffs, fellow veterans Lance Ball and Jeremiah Johnson and rookie C.J. Anderson.

"I've been in some really good rooms but this (from top to bottom), it's the most talented I've been around," said Hester, who played in San Diego with LaDainian Tomlinson and Darren Sproles. "There's not a guy where you can be like, 'Well, OK, we'll count him out.' There's no situation like that this year. There's not one guy who you can say, 'OK, this is his job.' Just because the competition is so great.

"It's going to be a competitive camp and there's going to be some good football players that are not here" when final cuts come.

The Broncos presume McGahee will return for their mandatory minicamp next week, lest he subject himself to possible fines.

McGahee, who became one of the NFL's most dependable runners despite tearing all the ligaments in his left knee during his last game in college, tore a ligament in his right knee in a game against San Diego last November and missed the rest of the year. Still, he led the team with 731 yards rushing.

McGahee has participated in some offseason conditioning, and while Montee Ball said he's glad to get so many reps so soon, he's looking forward to McGahee taking the field.

When McGahee got hurt last year, he was replaced by Moreno, who ran for 525 yards in six starts but was injured in the playoff loss to Baltimore. He underwent an operation over the winter in which stems cells were taken from the bone marrow in his pelvis and injected into his right knee.

"It was nothing really too serious," said Moreno, who tore his right ACL in 2011. "This time it was just a cleanup pretty much. And it feels pretty good."

Moreno did some pass-protection Monday as he started working his way back into the mix.

Many veterans who have been around as long as McGahee don't participate in these three weeks of OTAs, none of which are in full pads. But by not being here, he's missing out on the tweaks that new offensive coordinator Adam Gase has installed and he's giving the youngsters a big chance to begin carving out a niche for themselves in 2013 — which could put his own job in jeopardy.

"We've got some youth there and guys are taking advantage of those reps," said coach John Fox, who has noted diplomatically whenever he's asked about McGahee's absence that these OTAs are strictly voluntary.

Hillman has been practicing with the starters and Montee Ball has been getting some 1-on-1 tutoring from Peyton Manning after every practice to go over audibles, protections and other nuances of the pro game.

"We're going to count on him in a big way this year," Manning said. "He's a rookie but Coach Fox is not going to bring him along slowly."

Montee Ball is getting comfortable with Manning — and with the idea of playing with the four-time MVP.

"At first I was star-struck, I'm not even going to lie. I grew up watching him. Everyone knows Peyton Manning," said Montee Ball. "... Once you actually dial in, and actually get in your playbook, it actually all makes sense. He's been doing a great job, and it's going to continue, and I'm going to make sure I'm right there to contribute.

"It was funny because today I came in feeling extremely comfortable. Jitters are gone and now I'm ready to play and I feel like I sort of showcased that today in practice. I knew all of my assignments and I didn't look like I was a chicken with his head cut off in the backfield."

If that's the case, Hillman said, "he's better than me, because I had the jitters all year, every time I got in. He adapted a lot faster than me. But, I mean, you get to a level of comfort and familiarity when you're actually getting reps with the (starters). You're not nervous that Peyton is going to yell at you when you mess up. So it does have a good effect on you."

Hester, who joined the team just after Thanksgiving last season, is playing several different positions this summer.

"It's hard to find guys like that, to be able to play halfback, fullback, we throw him on the wing every once in a while, we can spread him out," Gase said. "His versatility is huge for us. It should help in our short yardage, goal line, four-minute packages. It's been a big point of emphasis this offseason to figure out how we get him on the field and use him a little more, whether he's playing tailback, fullback, an F-tight end and H-back. We're going to try to use him as many ways as possible."

Hester's versatility is perfect for a team that's planning to pick up the pace this year and run a more up-tempo style to keep gassed defenses on their heels. That means minimizing substitutions and with Hester, the Broncos can change the formation without running him off the field.

A lot is made of the Broncos' depth at wide receiver and cornerback, but the best competition at training camp might just be in their crowded backfield.

"Yeah, it's going to be competitive. Each one of us down to Jeremiah can play," said Lance Ball.

Whether McGahee shows up next week or next month, he'll see a much more formidable group of running backs he'll be trying to beat out.

Notes: The Broncos have hired John Spytek, who was the Cleveland Browns' director of college scouting from 2010-12, as their Southwest area college scout.